code: def test_cardinality(self, batch_size, device, dtype):
      inp = torch.zeros(batch_size, 3, 4, 4, device=device, dtype=dtype)
  
      op = Canny()
      magnitude, edges = op(inp)
  
      assert magnitude.shape == (batch_size, 1, 4, 4)
      assert edges.shape == (batch_size, 1, 4, 4)
  
file_path: kornia/test/filters/test_canny.py
imports: import pytest
  import torch
  from kornia.filters import Canny, canny
  from kornia.testing import BaseTester, tensor_to_gradcheck_var
  from kornia.utils._compat import torch_version
label_desc: Use image node_id 2 for calling the TestCanny obj's underlying member method code with example usage: obj.test_cardinality(batch_size, device, dtype) without return types